An important aspect of construction engineering is road construction and maintenance. The ability to design and construct roads based on future loads and environmental factors is very important as it saves time, effort, and resources in future maintenance costs. A well-designed road will have long-term performance when the design factors of loading, climatic, and soil conditions are accounted for properly.
In construction engineering, some of the most important properties of interest are volumetric and mechanistic properties of construction materials such as soil, asphalt, concrete, and the like. In particular, there are procedures in construction engineering practice that relate total volume Vt, mass of water Mw, and mass of dry solids Ms to the performance of a structure built on a soils foundation. Other important properties of interest are mechanical properties such as stiffness, modulus, and density. Thus, the measurements of these properties are important for construction engineering.
Asphalt and cement mixes used for construction typically remain relatively homogeneous and are well behaved unless problems such as segregation arise. In general, well-controlled materials can provide for the ability to calibrate non-nuclear and nuclear surface gauges with relatively good confidence. On the other hand, in most geographic areas, soils are inhomogeneous, and the earthwork required to excavate and fill on construction projects typically leads to areas and layers of soil of different mineralogy, moisture content, gradation, and texture. The result is that indirect methods of measurement, such as surface electromagnetic or acoustic instruments, frequently need recalibration when the operator suspects something in the base construction material has changed.
One of the most robust construction material measurement tools currently available is a nuclear density gauge. However, even this equipment is susceptible to limited errors as a result of the chemical composition effects. The largest error for nuclear techniques is in the water content which is used to correct the wet density measurement. If the composition under the gauge becomes richer in hydrogen than the original calibration site, then recalibration is necessary. For instance mica loaded clay and sand-like materials have different chemical compositions, and would need different moisture offsets or corrections. The problem comes when the clay/sand or mineral content varies throughout the scope of the project.
It is the purpose of the semi-empirical and mechanistic design methods to link laboratory tests and design criteria with the material work in the field. For instance, if a soil fails a laboratory resilient modulus (RM) test, the soil could be replaced with fill or strengthened with lime or cement. In the field, the soils are not typically homogenous, and can change as a result of climatic conditions such as temperature and moisture. For this reason, it is desirable to have quality control instrumentation and methods that can adjust for temperature and/or moisture effects. The results of such data can be helpful to construction personnel for determining soil and asphalt areas of low quality.
Techniques are known for measuring the modulus of construction materials. Generally, the measurements are obtained by generating an acoustic disturbance in the construction material and measuring a response of the material to the disturbance. For example, wave velocities of the response to the acoustic disturbance may be measured for determining modulus. However, the determined modulus in these techniques are subject to inaccuracies. It is desirable for providing correction to modulus measurements and generally improving the accuracy of modulus measurements of construction material.
Accordingly, in light of the above described difficulties and needs associated with nuclear density gauges, there exists a need for improved methods, systems, and computer program products for a property of construction material.